


The Only One

by Katakatica



Category: Undertale (Video Game)
Genre: Angst, F/F, F/M, Fluff, M/M, Possessive Sans, Post-Pacifist Route, Post-Traumatic Stress Disorder - PTSD, Prejudice Against Monsters, Reader Is Not Frisk, Romance, So much angst, Violence, Weirdness, sans could cross the barrier, sans does not remember the past timelines
Language: English
Status: In-Progress
Published: 2016-03-05
Updated: 2016-04-30
Packaged: 2018-05-24 22:46:49
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 4,686
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6169642
Author URL: https://archiveofourown.org/users/Katakatica/pseuds/Katakatica
Summary: <blockquote class="userstuff">
              <p>Sans met you a long, long time ago, way before he realized just how wrong he was with keeping his ability a secret. He was capable of teleporting to the other side of the barrier. He mostly just went to explore but one sunny afternoon that he fell asleep, you found him, suffering from a nightmare as dark as the night. And you helped him...and you were not scared of him.<br/>You did not see him after that for many, many years.<br/>But it did not mean that the two of you did not remember each other. After all, some events or even whole days just won't ever get forgotten, not even by children...</p>
            </blockquote>





	1. One

The first time you saw Sans, you had been but a child. You wandered off the road when heading home from school, wanting to catch the butterflies that roamed freely like souls around the area. You were allowed to do it as the little patch of grass was near to the small blue-white house your mother and father owned. Practically, it belonged to your family. You could recall your mother  thinking of making it into a flower garden, but your father had disagreed: it looked much better with all the vivid wildflowers and well, as there was no fence to protect it, nicely planted flowers could be stolen, too. You did not know the last fact, however, as you believed that little evil existed in the world. Maybe it was just how you had been raised, with so much love that would have been enough for twenty young humans like you were. You loved your life at that time: it had been peaceful and filled with wonders. Your parents had money, but they had even more love for you. You were an only child, for whom, even though they were both busy, they always had time. It was almost as if nothing could get more perfect. You felt like a princess, and had been raised like one. But despite that, no one would have called you spoilt. You may have liked your fairytales more than needed, but you had a heart as gold as the sun, and as big as the castle you wanted when you grew up. You were nearly perfect.

 That day, the very afternoon your life changed completely, Sans had been laying in the grass, snores escaping him. Hoodie nearly as blue as the sky was pulled into his face as he slept: because of that at first you did not even notice how he was not like you. How he was not human. You would not have cared anyway, your mind was still set on capturing at least one of the colorful-winger creatures. You were planning to look at it for a while before letting it go. You were not cruel enough to take it home or do worse to it, you just wanted to get a closer look.

Like other children, you were curious. You liked to see everything for yourself. You asked your mother why the sky was grey, then pleaded your father to fly with a near city to you so you could see it more (you ended up crying in fright and clinging to him through the flight, which made him chuckle inwardly. You were curious, but a little scaredy-cat when it came to being up high. He had known this would happen already, but he had agreed to what you asked as he hated seeing the disappointed look in your eyes when someone said _no_ to you. You never meant wrong, luckily, despite how many kids your age were already getting mean, incredibly demanding. You sometimes asked for big things, but always accepted it if one could not grant it to you. You just... cried a bit and found something to adore. Such a bright little one

.A skittish soul with the need to know everything, and the apparent fear of heights. Nothing else could make you scared, not even the monsters that were rumoured to live under your bed. One night, you asked your dear mama - you could not have been older than five, really - if the monsters were getting lonely, and if you could lie with them for a while. You were sad to realize that not one soul could fit the thin space under your bed, not even you. However, your mother told you not to worry: the monsters knew that you were not afraid, and that you would love to meet them. Only, they were a little shy. Just like you. Here, she had bopped your nose and kissed your forehead before tucking you in. After that came your favorite part of your night-time ritual: fairy-tales she loved telling so much. You adored listening to stories of princesses with dragons - dragons in these stories did not kidnap the princesses, they just helped them escape from the mean princes as you had begged your mother to change the storylines just a bit - or ones with the big bad wolf befriending Little Red Riding Hood. You adored that one tale so much: you would have loved to cuddle up to a wolf and pet its soft fur. You had a dog, but she was tiny and old with short fur. Lovely, but not what you wanted so childishly.

What was different on the field, was that while you ran freely amongst the grass and butterflies, your mother was not there to tell you stories. Because of that, you looked around and tried to come up with one of your own.

"The butterflies are dragons, and I am the princess. But I am the one catching them so they can show me their wings.." you babbled childishly as you walked, crouching down near the hoodie-clad figure. You were ready to pounce and grab at one of the butterflies clumsily when suddenly, soft sobbing shook you out of your. Curiosity beat you again and you looked towards the source of sound:flinching when you saw the form of the hoodie-figure shake. Was he (you assumed he was a boy from the deep-ish voice and the dark colors he wore) having a bad dream? You hated having those! You ran to help, nearly tripping over your own feet."Hey! It's okay!" you whispered."Waaake up!"

And he did, too tired that he was not back underground, where he could not encounter random human girls who seemed to care.

The first time Sans saw you, he had snuck out again. He was still young, maybe just a bit older than you were and too innocent to realize just how useful his magic could have been to the king and queen. He had childishly believed that everyone could teleport to the other side of the barrier like he could. After all, it was easy. He just had to think of the moon and the sun...or the stars. He was not a heavy sleepier: he often dreamt of things he had seen on his little adventures. This time, however, he saw dust everywhere, dark, heavy, deadly dust. He hated it, but he could not escape. He whimpered for his dad, for his Papyrus, his little brother, for anyone...

But nobody came.

It had been like this ever since his brother had been... made. Because of that, Sans didn't like Papyrus. He was loud and ate a lot, and he got hurt often. Their dad was always around him when he was home and because of that, he barely paid attention to Sans. Because of that, he often wandered away from home. At first, he just wanted his dad to come after him - not realizing that only he was capable of crossing the barrier - and then, his curiosity just grew and grew...

He woke to a tiny human stare down at him with wide, sparkling eyes."You are up! she cheered in glee and clapped her hands before introducing herself gleefully."Let's be friends, okay?"

Sans wondered if she even realized that he was a skeleton and well, she was not one.

The second time the two of you met was many, many years later.

And yet, you both could remember.


	2. Two

No one noticed how Sans was the only one who was not shocked by just how different - and similar to their old home - the surface was. Each and every monster was lost in their only little world, causing his odd attitude to go unnoticed by them. It wasn't that he was not enjoying the fading light of the setting sun: he was merely used to it. Even after he had last met you, he found himself wandering on the other side of the barrier often. Many times, when he was believed to be sleeping, he was up there, hiding in shadows, exploring. At times, he had wondered if he should have told at least the king that he was actually quite capable of passing the barrier, but something had not allowed him to do it. His very soul was pulsing, telling him that it was not the time.

He had not seen you since your very first encounter, however: the next time he had ended up in the small field, lying on the grass (and secretly hoping you would come), not a single soul had decided to wander around like you had. It was odd: he was sure that you had mentioned living close to him for some reason.

When a year or so later he went to check the house you probably lived at, he saw the large _ON SALE_ sign in front of it. He could not help but think about the reasons you could be moving. For him, it was odd: he had lived at the place with his dad and Papyrus for as long as he had been alive. The concept of having to live somewhere else sounded so odd to him at that time.

It was quite often after that that he tried to search for you but it was as if you had disappeared off the face of the Earth. He didn't like it, but he was too proud to admit that he missed you. He merely had liked the fact that you did not freak out when seeing you. After all, he was a skeleton and well, you were not. From what he gathered, humans did not believe in monsters anymore.

"Brother, isn't this beautiful?" Papyrus grinned down at him, voice a tad louder than Sans would have liked it to be. He nodded still, flashing his usual grin to his brother. It was a little fainter than usual: he did not like remembering you,  mainly because he had long lost hope of seeing you again, but Papyrus did not seem to mind. He was too dazzled, too enamoured by the novelty of his new surroundings. It was a little funny in a way, but Sans did not have the heart to laugh at the eager monsters. Maybe it was him who was a little faulty, maybe it was him who was too used to the surface.

But really, what was so special about it? Sure, there was the sun and the stars, but that was it. Monsters had lived happily underground for a long time and he was almost sure that they would have long forgotten about the life they once had if there had not been so many legends, so many elders wanting to go back there.

Then again, wasn't Sans the same? Despite how he tried to push the wretched feelings back into the depth of his soul where they belonged, he could not completely ignore the hope and fear that lingered there. He had searched for you in secret for a long time, but he had never fully given up. A tiny, tiny part of his still thought that there was a chance for the two of you to meet. Maybe you would come back, maybe you would just... meet somehow. After all, just how many humans could live on this planet? What was the chance of him not seeing you again?

Apparently, there were a lot of humans inhabiting the slowly dying planet of Earth. You were merely one of them, living in a dull city with a routine you had been doing for the past three days. You woke, went to school, then work and back home. You had a lot of friends, but rarely had the time to hang out with them. After all, you lived alone now, with little help from your parents. You didn't need it, anyway. They had it rough themselves after the fire in your father's company. Life had not been the same since then.

With a sigh, you turned off the shower and stepped out of your shower, a shiver running down your spine as cool air hit you. It was early, way too early to be awake, but you had a class at nine. To get there, you needed to take the train: and it took an entire hour. It was not because you lived so far away from campus: unfortunately the only train that actually stopped both near it, and your little apartment actually stopped at each and _every_ between the two. At a few, it even waited for five minutes. You hated it.. then again at least you did not need to walk. It was still better than that, especially in the winter.

You tossed on your clothes, a pair of simple jeans and some weird T-shirt that had roses on it. You got it with a couple friends and while it was not exactly your style, it still looked good on you so you wore it from time to time...Especially when you had classes with those friends. You grabbed your thick coat and scarf before you darted back to your room to get your back, having forgotten it there. You have always been so forgetful..especially since weird skeletons and blue flashes have occupied your dreams.

Ready for the day, - and pushing the thoughts of your nightmares away for the time being - you threw your door open and stepped out in the long corridor. It was so cold, like you had stepped on ice, or at least something equally as chilling.

A glance down at your bare feet made you realize just why.

You wailed to yourself in frustration and backtracked for the second time that day, cursing your silliness. Just as you were about to leave finally, you realized that you had left the TV on in your room. Just how could you have missed that? With a sigh, you trampled back, boots already on. You were ready to toss something against the screen repeatedly until it turned off - it worked often, you just needed to replace it from time to time, really, but something made you halt your movements.

There were monsters parading on the screen, bright, happy and real..

And a skeleton in a blue hoodie stood in the midst of the crowd, looking unimpressed as one could be. You, however, were not, cheeks blushing madly as you recognized him. But... he had changed...

Glancing at your reflection in the mirror before looking back at the TV, you had to admit that it was not only him: you had changed a lot, too. Just how odd the world could be?

**Notes for the Chapter:**

> Whew, writing this was hard. I am not completely satisfied because it could be better, but I feel like this is the best I can write lately so..yea :D There will be a lot of flashbacks to Sans travelling from down to up (lol) but I decided to do the time-jump now, for reasons :) Poor reader tho, didn't have such a bloomin' life so far. Then again, it could have been worse. Thanks for the comments and kudos and all that, I reaaally appreciate it <3 made me feel a bit more confident haha :P Hope this second chapter was good enough to keep your attention :P  
> Love,  
> Kat


	3. Two

By the second time Sans saw you, he had lost all hope of meeting you again. Life on the surface for him and his kind, _monsters_ , was everything but easy. Humans did not turn out to be as accepting as they had once seemed to be. It was never anything major, just a nasty glance or two, or hushed whispers about how _someone_ did not belong. No matter where they were.

Sans wasn't exactly bothered by it. He had expected that things wouldn't be perfect: it would have been too easy. His brother didn't take it too harshly either: he would oftentimes announce that the humans were probably just intimidated by his awesomeness. Sans didn't have the soul to tell him the truth.

It was a warm summer day, maybe six or more months after the barrier had been broken. The sun was high up in the sky and the stench of sweat polluted the air. If Sans had a nose, he would have scrunched it up. Humans smelled worse than monsters by default - or well, if not worse, very different from them - but now, now it was just _horrible_ to be around them. And he had to be: he was, after all, working one of his way-too-many jobs. As a hot dog vendor.

At least it came with free ketchup.

He did not hate the job mostly, really. The pay may have been low but his boss was okay and around the busy little park he worked at, most people didn't really care whether he was a monster or not: they bought the food from him anyway. Cold comments did not hurt him, but they still got a bit annoying after some time. He preffered people who gave him their orders, took their food and left - not without giving him a tip, of course. While living was not as expensive as it could have been considering the situation, Sans liked to have the best in everything. Big house, sports car for Papyrus and everything else they probably did not even need. The gold they had brought had great value despite the looks of the workers who had been _forced_ to exchance them. The skeleton could actually remember the chubby old man that had been working on his case.

He had grumbled under his moustache for the thirty minutes he counted out the money for Sans and his brother. He had even made a show of not giving it to them - _afraid_ of touching such _horrifying_ creatures, - placing it on the table in front of the monsters as if it would be so insulting. Papyrus just took it and grinned, thanking the _unkind human_ a couple more times before marching out of the office like he owned the world.

Sans sometimes wondered how he did that.

He ignored things, too, but he did not act as if they were... positive. Sometimes, he envied his little brother of his ability to view everything so brightly. He was just so... happy like that.

Then again, Sans _could_ have been happy, too. He knew it. Something was just missing.

That something butted into him on that way-too hot day. He was just about to go on his lunch break, grabbing his bottle of ketchup - and for once, a hot dog, too, deciding to try if what he was selling was actually edible - when a soft voice made his movements come to a halt.

"Uh, you are open still, right?" even without looking, he knew it was you. Your voice had barely changed, it had just gotten a little deeper and mature. It held a sad edge, but.. it was still you. He looked up at you slowly, wondering what your reaction would be.

Both of you just stared for a while.

In the shining sun, under the bright blue sky, you looked beautiful. You hadn't changed as much as he had thought you would, though he could recall your hair being a different color. He knew that humans liked to change it, however, so he didn't care much about that little fact. You still had kind eyes and heart-like lips and a small nose, but you had also gained dark circles around your eyes. You also seemed pale, almost sickly so. Where had the healthy glow of your skin gone? He wondered to himself, but he said nothing.

He just stared, just like you did.

"I would like a hot doig." You muttered, surprise clear in your gaze. You wanted desperately to say something, to ask him if he remembered... to say anything. But you couldn't.

The skeleton had not changed much. He had clearly grown quite a bit - though he was still somewhat short, which you found somewhat amusing - and his hoodie seemed to make him seem even bigger. The lights of his eyes were brighter and his grin as wide as ever. It seemed genuine, but there seemed to be something around its edges. Worry? How could he even mouth his teeth like that? You shook your head a bit: you couldn't let your thoughts wander. You had a job to get to in twenty minutes and you still needed to eat. It would have been nice to catch up with the skeleton for sure, but... You weren't sure what you could have said. Your life was everything but exciting.

"Uh," Sans looked at you for a few more moments before finally shaking his head a bit," it's on the house...friend." he added, the last word being a little hint to what you had told him so many years ago. He could not help but hope that you did remember and you were just shy to take the initiative. You looked like someone who would be like that, really.

"Thanks, friend." And you smiled just a bit as he handed you a hot doig. It was sloppily made - much like the one he had placed on the counter of his small cart, but it looked delicious. Then again, even wood would have looked appetizing to you at that moment. You had skipped breakfast again. Even with working, there were times when bills proved to be more important than food. And you were not the only student like that. It seemed like your age group was cursed. Or..something like that.

"So..." he started awkwardly, and you swore that his cheekbones had gained a faint blue glow. Was that normal? You tilted your head to the side as you bit into your food, a grin growing on your lips. You nearly moaned in contentment: it was really good.

Or..was it hunger talking? You weren't even sure why you were smiling so much that day. School had been horrible and your job had not started out too well. But then you saw him and... your worries had slipped away. Maybe it was the familiarity that calmed you a little. Or maybe you were going insane.

Yeah, the latter seemed like a more probable answer to your inner musings.

"So... I will go on my break now," he said lowly, a sigh escaping him before his eyes brightened." Wanna _ketchup?" He pointed at the large bottle he had discarded next to his hot doig._

_You blinked before narrowing your eyes._

_Was he for real?_

**Notes for the Chapter:**

> wow. finally I wrote something. It's not too good but considering my major writer's block it means the world to me. Haha. Thank you guys for the support anyway ^^


	4. Chapter 4

The two of you didn't have the time to chat for long, but oddly, it was more than enough to put a smile on your face. This time, it was not a faux grin you used to fool others: it was small but genuine, and to Sans, it was brighter than the sun itself. You caught him staring at you a couple times and you could not help but feel just a bit flustered. Maybe it was because you did not go out that much, but it had been quite long that anyone had observed you so closely. If anything, it was pleasant to finally converse with someone like this.

Freely.

You didn't mention the past you shared. For some reason, both of you seemed to have decided that it was unnecessary. You talked about anything casual: from the weather to where you worked at or even why you were there at the first place. Nothing deep, nothing touchy.

Almost as if you have met for the first time. It was somewhat funny, you had to admit to yourself. The skeleton was everything you had remembered him to be and more: he was, if possible, quirkier than he used to be, and his puns had admittedly gotten better. They still were everything but hilarious, but at least he tried.

You didn't ask him about where he had been or how he had ended up here... Nor how he recognized you. You wanted to, so badly, but... You felt as if wasn't your place. After all, the two of you hadn't met so many times. You were merely acquaintances, nothing more. Only, you called each other friends. But what did that mean anyway?

Why did you let darkness cloud your thoughts again?

You had parted with promises of meeting again and small, shy hug. You had been the one to initiate it: for a strange reason, it had felt right. Maybe it had been the sparks of insanity that were buzzing in your soul..maybe it had been the sheer fact that you craved contact... or that you have missed him.

He had been surprised, cheekbones dusted a light blue as he lazily patted at your back. And yet, no hug before had felt so _right_ before. It had been short and brief and awkward and yet.. It had been all you had needed.

"Will you be here tomorrow?" you asked quietly as you turned to leave truly, biting down on your lower lip. The pinpricks of his eyesockets darted down and you could see him lean in further just a bit, a thoughtful grin on his lips. What was he looking at?

"I will," he said finally, voice a deep rumble."Same time then, friend?" he asked and you nodded, your lips once more curling into a small smile.

And then you were off, quick on your feet. You had to rush to your workplace, after all.

It took quite a few minutes for Sans to be shaken back to reality. He had been dazed by the little hug you had given him: the scent of flowers and sunshine, that was still entirely you still hung heavy in the air around him. A part of him scowled: he should have said something wittier. Or..maybe he should have prodded. He should have asked where you had been, why you had not been back in the garden, waiting for him?

Then again, wasn't it a wonder that you even recognized him? The two of you had just met once, barely. You had been children, young with minds filled with curiosity and glee.

He let out a sigh. Thinking about you was making his brain ache - and he technically didn't even have a brain. It was weird. While he had been overjoyed to meet you, there was still an odd pang of emptiness in his soul. Maybe he had expected something else? It wasn't as if the two of you could have openly chatted about your first meeting, not with actual people around, who knew nothing of his old ability to cross the barrier, but...

As his shift for the day ended and he started walking to the house he shared with his brother, he finally recognized the strange emotions swirling in his mind: he was already missing you. It was crazy he knew, but he could not help it.

Maybe it was how much he had thought of you.. Just a little meeting could not erase the memories of him searching for you frantically, thinking that you were just hiding, fooling around, playing with him. Then again, then, he had been a child. A _babybones_ as his father had often referred to him. Now he was grown and through many things in life. And so were you.

He hoped that once he met you again, his weird feelings would go away. He could not help but feel how _wrong_ they were. He was already thinking of seeing you once more when you had said goodbye just hours ago. He should have been thinking about anything - or anyone- else. Like his brother. Or the human that freed him and his race. Or the queen he still visited from time to time because she was so damn funny. And yet, you were the only one on his mind.

A human. A weird one at that, one he had only met for so long.

Sans did not even realize that his left eye was blaring an electric blue as he walked. His magic buzzed around his short but powerful form, ready to take him anywhere... or to hurt someone.

Before he knew it, he was swept off his feet by the very familiar sensation of one of his many shortcuts swallowing him. But this time, he had no wanted it to happen. He had been walking to clear his mind, after all.

He did not protest however, allowing his magic to lead the way. For an odd reason, he was not even surprised when his destination had been an unfamiliar room, housing a very familiar girl.

Thank god you were asleep despite how early it was...

Just what was he doing at your place, anyway?

**Notes for the Chapter:**

> Oh god this took me too long :/ Sorry about it guys.   
> uh  
> I hope you don't find creepy sans too unsettling. I do, but this is necessary for the plot (something IS wrong haha.   
> there is always something wrong when I write a fic. why. why can't i write about roses and faeries?)  
> anyway, feel free to comment on how silly my writing is :D or.. drop me a message or whatever. my tumblr is katakatica (duh :D) so..yea. there's that.  
>  #shuffles away awkkward


End file.
